1. Technical Field
The preset invention relates to a wiring structure, a droplet discharge head, and a droplet discharge apparatus.
2. Related Art
Droplet discharge apparatuses including a droplet discharge head that discharges a droplet are used for, for example, the formation of image or the manufacture of wiring of micro devices.
For example, a piezoelectrically-actuated droplet discharge head includes reservoirs that store ink, a plurality of pressure generating chambers in communication with the reservoirs, a plurality of nozzles respectively in communication with the plurality of pressure generating chambers, a plurality of piezoelectric elements that respectively vary the pressures in the plurality of pressure generating chambers, and a driver IC that drives the plurality of piezoelectric elements.
In the droplet discharge head, as disclosed in JP-A-2006-281763 (Patent Document 1), the piezoelectric elements and the reservoir forming substrate (wiring substrate) formed with the reservoirs are generally bonded to one surface of a channel forming substrate (base substrate) formed with the pressure generating chambers. The driver IC is bonded to a surface of the reservoir forming substrate opposite to the channel forming substrate, and electrically connected to the piezoelectric elements via wirings disposed on the reservoir forming substrate.
Between the driver IC and the piezoelectric elements, a step due to the thickness of the reservoir forming substrate is generated. The driver IC and the piezoelectric elements need to be electrically connected via the step.
Therefore, in the droplet discharge head disclosed in Patent Document 1, a side surface of the reservoir forming substrate is formed to be an inclined surface. On the inclined surface, the wirings that electrically connect the driver IC with the piezoelectric elements are formed.
In recent years, it is desired for realizing the formation of image or the manufacture of wiring with higher definition to reduce the pitch between the nozzles. As the pitch between the nozzles is reduced, the pitch between terminals of the piezoelectric elements is also reduced.
In the droplet discharge head disclosed in Patent Document 1, however, since a surface on which the wirings are formed is one side surface of the reservoir forming substrate, the minimum pitch between the wirings is about the same as that between the terminals of the piezoelectric elements. Therefore, when the pitch between the terminals of the piezoelectric elements is reduced, there arises a problem that the formation of wiring is difficult.